Need help with MX6...

Cincymx6

Member
Hey guys, thanks for the help in advance. Alright... here is the situation. My car has spark, and 150PSI compression in each cylinder. The timing is perfect I have changed spark plugs, Wires, Disty... cap and rotor... Crank shaft position sensor... ecu and fuel rails/Injectors. My problem is... whenever I try to start the car it just cranks and cranks. When its cranking though, instead of detonating the fuel it just dumps it into the exhaust and it leaks out of the exhaust manifold. there is no fuel hose leak its definitely internal. Someone had mentioned a Fuel pressure regulator, so I will probably do that today... But does anyone else have any idea's??? My car is a 1993 mazda MX6 6cyl. LS. Thank you for your help again =)
 
ok if you are dump fuel out of the exhaust I would have too look at two things. Timing and ignition. Only thing I can come up with is to recheck the timing and the ignition. The kl is known for having crappie ignitor. Even if you got a remanufactored unit there is a chance the ignitor is bad. Mazda released a new design for the 93-94 system which is what I have on my 93 pgt. Very costly because only mazda sells them. Parts stores either sell a remanufactored unit or a unit of the same design of the orginal failed design. Also, when checking the timing, I think the KL uses two sensors for timing. One is the crank position sensor and the other is a timing sensor located in the distributor.
 
sounds like you have fuel pressure if you have fuel being dumped. Simple check would be like this: Looking at the engine on the left side there is a fuel line that connects the two fuel rails. The system should be under pressure at all times. Pull this line and fuel should surge out. Have someone crank the engine and fuel should shot out. Ghetto way of checking fuel pressure. But like I said if you have fuel dumping out of the exhaust manifolds then the fuel seems like it is being delivered. The timing maybe so far off that there is no spark when the fuel is delivered or/and fuel is being delivered on the wrong strong. With the two sensors, crank postion sensor and the disty timing senor, the ecu figures out from those values when the fuel should be delivered to each cyl. The ecu sends a signal to the injector to fire a pulse of fuel. Trust me you wouldnt be the first person to have multiple problems with the ignition system on the KL serie engine!
 
yeah... but what I was thinking is... that the fuel pressure regulator is not regulating at all.. and there is too much pressure... is that possible?
 
Sorry to interupt but the MX6 isn't a "6" so it is being moved to the correct forum.
 
Cincymx6 said:
yeah... but what I was thinking is... that the fuel pressure regulator is not regulating at all.. and there is too much pressure... is that possible?

A fuel pressure regulator is like a blatter and increase and decrease from a vacuum line. More vacuum and the blatter decreases in size allowing more fuel into the fuel rails and giving the injectors more fuel to spayer. Fuel would only be delivered when the injector was given the signal to do so by the ecu. The thing that is with raw fuel being pushed out of the exhaust ports usually means that timing is off or the off chance that there is no spark. The first thing I would do would be to re-time the car. Just to ensure that is correct. I would also cheap the ignition and see if there is spark being made. After that is checked I dont know what to tell you.
 
heh, both have been done... =( but I just bought a new engine... 600 bucks after a fresh rebuild... so I guess thats the answer to my problems...
 
probably have same issues... just because you replace block and all dont mean the dis isnt stil bad.. yes new rebuild should be blue printed and balanced properly allowing the timing to be correct :)
 
Probably a stupid question, but are all of your fuses good? It's worth a look IMO.
 
yeah, all my fuses are good... Tried a brand new disty today... still no start... I was thinking maybe ignition switch??? Or something to do with this alarm i have on it... It has a remote start.... any other idea's?
 
Cincymx6 said:
yeah, all my fuses are good... Tried a brand new disty today... still no start... I was thinking maybe ignition switch??? Or something to do with this alarm i have on it... It has a remote start.... any other idea's?

Those definately sound like viable places to investigate.

The only thing I can think of is check your timing again. It happens all too often (and is easy to do) that the timing looks right, but it's 180* out. Also, be sure you are using the #1 cylinder to set TDC (I.E. choosing the first piston on the left bank versus the right bank at the front of the engine).
 
I hope you find your problem and post the solution so I can fix my headache also . Yea I have the same problem with a 96 MX6 v6 2.5 it has fire to the plugs it has 150 psi compression it has the proper fuel pressure the valve timeing has been checked the data stream shows all sensors in range the ecm shows all normal readings with a pin voltage check the exhaust is not stopped up . the only thing wrong is the injector drive signal is wide open
and flooding the plugs HELPPPPPPPPPPPPPPPPPPPPPP!!!!!
 
* Note from the Admin...Let's try to keep the topic going on this forum instead of leading new members away...Thanks :D
 

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